The current I passing through a wire in terms of its area cross-sectional area A, electron number density n, the charge of an electron e and the mean drift velocity of electrons in the wire v using the formula:
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Measurements for the current, diameter and mean drift velocity are made for a wire of circular cross-section and the value of e is taken to be a universal quantity with negligible uncertainty.
The current is measured to be (0.5 ± 0.01) A, the diameter of the wire is measured to be (1.00 ± 0.01) mm, and the mean drift velocity of the electrons is measured to be (0.35 ± 0.01) mm s-1
What is the uncertainty in the value of the electron number density of the wire’s material to one decimal place?